AES E-Library

A Parametric Instrument Codec for Very Low Bit Rates

A technique for the compression of guitar signals is presented which utilizes a simple model of the guitar. The goal for the codec is to obtain acceptable quality at significantly lower bitrates compared to universal audio codecs. This instrument codec achieves its data compression by submitting an excitation function and model parameters to the receiver instead of the waveform. The parameters are extracted from the signal using weighted least squares approximation in the frequency domain. For evaluation a listening test has been conducted and the results are presented. They show that this compression technique provides a quality level comparable to recent universal audio codecs. The usability however is at this stage limited to very simple guitar melody lines.